The Gerald Desmond Bridge project will be delayed by 12 to 18 months because the designs for several parts of the project have taken longer than expected. Artist's rendering of the completed bridge.

The Gerald Desmond Bridge project will be delayed by 12 to 18 months because the designs for several parts of the project have taken longer than expected. 8-foot sections of an old oil well are stored next to the old well where they were removed before being hauled away. The new bridge will be built along this path on the north side of the current Gerald Desmond bridge. File photo. Sept. 13, 2013. (Scott Varley / Staff Photographer)

LONG BEACH >> Building the state’s first major cable-stayed bridge, an important structure that links Terminal Island and the 710 Freeway to the nation’s trade system, has not been an easy feat for the Port of Long Beach.

After harbor officials broke ground on the project in January 2013, crews began the arduous task of clearing the path for the construction of a span to replace the tired Gerald Desmond Bridge, relocating utility lines, capping old oil wells and demolishing the old maintenance building. Some of those issues prompted officials to ask the Long Beach Board of Harbor Commissioners for more money.

Now, engineers, who have already completed about 65 to 70 percent of the design work, are encountering bigger issues in designing the new bridge’s foundations and its towers, complications that officials this week said will delay one of the port’s biggest projects by 12 to 18 months and push up the costs of a $1.263 billion project that has already seen budget increases.

How much more of a budget increase remains to be seen, but it will likely be incurred from added redesigning, cost for materials and other expenses associated to the delays.

Port spokesman John Pope said costs will be driven by the design that will be approved. He did not want to speculate on whether that increase could be in the millions or hundreds of thousands for the bridge.

The project is being funded with a combination of port revenue and federal and state funding, Pope said.

The designer will submit preliminary estimates in early July to port staff, who will present it to the commission in the coming weeks.

The project is a priority for the commission. Built in 1968, the Gerald Desmond, which helps to ferry nearly 15 percent of the nation’s waterborne cargo, has been slowly crumbling over the years — so much so that nets had to be attached to the bridge to catch falling debris.

When completed, the new bridge will stand taller to accommodate larger ships and will feature additional traffic lanes, separate bicycle paths and pedestrian walkways.

“I’m really concerned,” Board President Doug Drummond said Tuesday. “I realize it’s an engineering problem having to do with design and being earthquake-safe. If it’s about safety, I understand, but we also need to get an adopted plan.”

The issue for the delays are twofold, port officials say: the design of the bridge’s foundations and its 500-foot-tall towers.

Engineers did not anticipate the complexity of the soil makeup; engineers have had to design each set of foundations individually due to problems found in the ground.

“On a lot of projects you can take a lot of different soil samples and it will be fairly consistent, but there’s almost no consistency in the port environment,” Pope said, adding that the different layers of soil composition ­— a swirl of clay, sand, dirt — affects the evenness and stability of the soil.

Building some of the bridge’s foundations on Terminal Island has also complicated the design work because of the island’s subsidence issues, Pope said.

“It’s just a very challenging environment,” he said. “It’s going to take a lot more work to make sure it’s being done right.”

Design of the bridge’s towers are also being revised to get the right mix of strength and flexibility in the event of an earthquake.

“There’s no off-the-shelf plan for designing this in a port environment,” Pope said. “It’s the complications of the soil conditions, the very unique nature of Terminal Island versus the mainland and the fact that we straddle two very different soil conditions that has added many layers of complexity to the project.”

Port staff is working closely with Caltrans, the agency that will take ownership of the bridge once it’s built, to keep the design and review process moving forward. Caltrans remains committed to the project at the very highest levels of the department to ensure that the bridge is an enduring structure, said Judy Gish, spokeswoman for Caltrans.

“They’re designing this bridge to last 100 years,” Pope said. “It’s about taking the time to get it right.”